Building a Pinhole Viewer
Materials
cardboard tube
black construction paper
aluminum foil
wax paper
4 rubber bands
pin
Procedure
Place aluminum foil over one end of the cardboard tube and use a rubber band to hold the foil in place.
Place wax paper over the other end of the tube and hold the paper in place with a rubber band. There should be no wrinkles in the wax paper covering the opening of the tube.
Roll a piece of black construction paper lengthwise around the tube. The foil end should be flush with one end of the construction paper as shown. Use two more rubber bands to hold the construction paper in place.
Verify that the wax paper end is now in the middle of the black construction paper tube.
Use a pin to make a hole in the center of the aluminum foil. You may have to enlarge the hole slightly to see an image clearly.
Point the pinhole toward a light source and look through the other end of the viewer. Observe several objects inside your classroom (chairs, tables, and books) and outside of your classroom (houses, trees, and cars). CAUTION Do not use the viewer to look at the sun, as you may injure your eyes.
Analyze and Conclude
Observing Describe the images that appeared on the wax paper.
Relating Cause and Effect What caused the images to appear on the wax paper the way they did?
Reviewing Concepts
Name the two main types of telescopes.
How does a film camera work?
Describe the system of lenses in a compound microscope.
What is the purpose of the lens in a camera?
Critical Thinking
Inferring High-speed film is very sensitive to light. Explain how this could be useful for dimlight photography.
Applying Concepts Can the image seen in the eyepiece of a compound microscope be projected on a screen?
Speed of Light From Chapter 18 you know that light travels at an extremely high speed. Explain how the images of deep-space objects you see through telescopes are images of the past.